Problem: If $a + b = 6$ and $x + y + z = 1$, what is $-2x - 2z - 2y - 5b - 5a$ ?
Explanation: $= -5a - 5b - 2x - 2y - 2z$ $= (-5) \cdot (a + b) + (-2) \cdot (x + y + z)$ $= (-5) \cdot (6) + (-2) \cdot (1)$ $= -30 - 2$ $= -32$